That looks beautiful! I've looked closely, and I really can't see much of a problem with the wall to tower transition, and I actually love the blue roof. You obviously hold yourself to a very high standard. Just be careful that you don't spend so much time on details only you will notice that your quest never gets finished.
We have been telling him this for years.
Great job, Migo; it looks fantastic. I agree about the transitions between the walls and towers. A slightly different blue for the water may be good as well, though this is probably only necessary if you are keeping the blue rooves: the two blues do not compliment each other well. The pillar without damage may look better if it takes the place of the one closest to the castle--at least, it may look better. At any rate, nicely done.